Thermal responsive venetian blind



Nov. 29, 1949 J. .LGREBE THERMAL RESPONSIVE VENETIAN BLIND 2 Sheets-Sheet 1 Filed Oct. 22, 1945 v INVENTOR JOHN J. GREBE Nov. 29, 1949 .1. J. GREB.E 2,489,879

THERMAL RESPONSIVE VENETIAN BLIND Filed Oct. 22, 1945 2 Sheets-Sheet 2 INVENTOR JOHN J. GREBE Patented Nov. 29 1949 UNITED STATES PATENT OFFICE 2,489,879 THERMAL RESPONSIVE VENETIAN BLIND John J. Grebe, Midland, Mich. Application October 22, 1945, Serial No. 623,673 9 Claims. (Cl. 268-96) This invention relates to Venetian blinds and particularly to a type thereof which will be self operating in response to either solar or ambient heat.

In providing sun shade means for windows and similar openings it has long been common to provide outside awnings of one type or another. These operate with a reasonable degree of satisfaction but yet have certain drawbacks and disadvantages. Among the more obvious of these drawbacks are their rather unsightly appearance, the frequent necessity of operating them from the outside of the building and, particularly, their lack of flexibility in that it is not usually possible for an awning to shade only the portion of a window which is receiving direct sunlight and leave other portions with an unimpaired view. Some of these disadvantages are avoided by using conventional inside Venetian blinds, but in doing so a great portion of the solar heat which an awning is able to keep out of a building is permitted to enter by inside Venetian blinds. Hence, even though inside Venetian blinds will provide shade and protect the interior of a room from the direct rays of the sun they will not keep the room nearly as cool as will an outside awning.

It is accordingly desirable to provide a means which will combine the neat appearance and flexibility of the Venetian blind with the more effective shading of an outside awning, and in addition provide independent and automatic operation of the various portions of the blind to keep the individual parts thereof properly adjusted in relation to the sunlight falling thereon at any given time. In this way the blinds will be open to admit sunlight in the morning and evening when the sun is low and its rays are not particularly hot, but will automatically close suf ficiently to protect the interior of the building from excessive heat when the sun is high and/or hot. Further, in certain forms of the hereinafter disclosed invention the elements of the blind operate individually so that where a part of the blind is in the shade it will remain open while the part of the blind which is in the sun will close.

It is further desirable that units which will meet the above outlined conditions shall be inexpensive to construct, easy to install, reliable in operation, and attractive in appearance.

Accordingly, the principal object of my invention is to provide an automatically operating Venetian blind applicable to the exterior of a window or similar opening in a building.

A further object of my invention is to provide an outside Venetian blind as aforesaid in which 2 the individual elements thereof operate independently of other elements.

A further object of my invention is to provide an outside Venetian blind having individually operating elements which will be inexpensive to construct, easy to install and reliable and accurate in operation.

A further objectof my invention is to provide means for operating Venetian blinds automatically which will be applicable to a wide variety of specific installations including inside installations.

Other objects and purposes of my invention will be apparent to those acquainted with equipment of this type upon examining the accompanying drawing and reading the following disclosure.

In the drawings:

Figure 1 is a somewhat schematic view in central longitudinal section showing the manner of installing my outside Venetian blind onto a window.

Figure 2 is an enlarged detail view of two units of one form of my improved blind.

Figure 3 is a fragmentary front View of the form of my improved blind shown in Figure 2.

Figure 4 is a fragmentary front view of another 'form of my improved blind.

Figure 5 is an enlarged fragmentary end view of a further form of my improved blind.

Figure 6 is a form of my improved blind adapted for inside installation.

Figure "I is an enlarged fragmentary end view of the form of my improved blind taken along the plane VII-VII of Figure 4 showing a typical installation of one of the shading elements in open position.

Figure 8 is a fragmentary view of the form of my improved blind shown in Figure 7 and taken along the plane V1II-VIII of Figure '7.

Figure 9 is a fragmentary end view of a further form of my improved blind showing a typical installation of one of the shading elements.

Figure 10 is a fragmentary view of the form of my improved blind shown in Figure 9 and taken along the plane X-X of Figure 9.

Referring first to Figure 1 there is shown a fragment of an ordinary window frame I having therein a conventional lower window 2 and an upper window 3. Outwardly of the conventional blind stop 4 there is mounted for pivoting in the plane of the broken line Bin any of the several ways shown hereinafter the individual blind slats 5 which, as shown in Figure 1, may occupy a series of difierent and independent positions.

This particular series of positions as shown in Forms shown in Figures 2-4 Referring now to Figures 2 and 3 there is shown one form of specific construction. A blind element 7 holds at its one end a pivot rod 9 which is pivotally supported by a bracket 8 of any convenient type, said bracket being suitably fastened to the window frame IE]. At the other end the blind element is supported by a connecting plate I I onto a control wafer I2 which is mounted onto the window frame I3 by any suitable bracket means I l and I5. It 'should be understood, however, that this particular embodiment shown is only an example of several others which will be selected in a given'case' according to the specific needs which have to be met. For example the control wafer I2 may be duplicated on each end of the blind element l in larger installations, or where a more exacting control is desired. Further, the control wafer -I 2 may be mounted directly onto the blindslat TeX-Figures 4, 7 and 8) and appear as a long relatively narrow element I'2a for the more positive controllingof the blind slats.

When such an arrangement is employed the blind slat la as well as'thecontrolwafer I2a is interposed between theends of the lower pivot bracket :62 dividing said bracket into an upper portion I03 and a lower portion I04; "The lower portion I04 is attached to the lower surface of the blind slat 7a. and the upper portion IE3 is'attached to the control wafer I2a. Afurther variation (Figures9 and 19) would replace the blind slat/entirely by an elongated fe'xpan'olible' control wafer I55 having a cross-section"substantially similar to the diametric cross-section of the control wafer a f 2 and 'iriount'edin a 'siihilar'manner whereby'the 'slat and the control wafer "are combined into a single element, The control'wafer I2 "(Figur'e2) has a mounting plate It on its one side'andamounting plate IS on its othersidel' ,To these mounting plates are secured the pivot brackets I! and i8, respectively. An upperbracket I9 is fastened to the Window frame in a convenient manner, and the lower bracket I is likewise fastened tothe window frame in any convenient manner. The upper bracket 1 SleXtends a short distance from the surface of the window framejthe exact magnitude of which distance willbe determined by the relevant design details in any given installation. Aconnectinglink 2| is pivoted at 22 to the upper bracket I9 and'at-2 3'to the upper pivot bracket I8 of the control wafer. The lower supporting bracket I5 is fastened-.pivotally at 24 to the lower pivot bracket il ;of'the control wafer. The length of the connecting link 2i and the arrangement of all parts are such that a line 25 from the pivot point 22 through the pivot point 23 will fall outwardly with respect to the building of a line 2t drawn from the pivot point 22 through the pivot point-24 for reasons appearing-hereinafter. Thus the link 2I and the wafer with its pivot brackets forman outwardly bent-toggle based at point 24, wherein the lower, or shorter, leg of the toggle is extendible.

' placed in the upper member of the toggle, the

forth at length here.

operating arm 45.

the same as the wafer Figure 2 is,inserted'between the lower part -49 The wafer I2 is constructed of corrugated metal of sufficiently thin section to be flexible and is formed into a body having a gas tight hollow interior. This interior is filled with any one of a number of low boiling materials, such as chloroform, methyl or ethyl alcohol, or ethyl ether. However, it should be understood that any material can be used within the wafer which will boil at or a little below the temperature at which it is desired to have the blinds closed. Since the actual closing will be a function of the pressure developed within the wafer as well as a function of the boiling byitself, the exact turning point will be determined by both the choice of liquid and the amount thereof put within a given wafer. This, however, is conventional with respect to wafers of this type and hence need not be set A desirable temperature for the turning of the blind slats is approximately 95 F. so that the character and amount of the liquid used may advanta'geously be chosen to cause expansion of the wafer under substantial pressure at that temperature.

The expanding of the Wafer may also be controlled by the manner in which it is colored or coated. By usinga dark or heat absorbing color the wafer will be extremely'sensitive to the suns rays and cause the slats of the blind to respond thereto with relatively little regard for the actual air temperature surrounding. On the other hand by providingthe wafer with a mirror-like, or other reflecting, surface the suns rays will have little efiect thereon and the response of the wafer will be primarily to'th'e air temperature surrounding.

Referring again to Figure 2 it will be seen that when'the wafer is caused to expand it will exert a pressure tending'to 'open'the angle between the broken lines 25 and 26. This then causes the pivot 'point 23 to move to the right to assume the position shown in the lower half of Figure 2 and thus cause the slat -'I to pivot around the pivot point 24 and assume the position indicated in t:.e lower half of-Figure 2. v

It will be evident that by proper selection of link and bracket le gths and angles the degree of turning of the slatscan-be made practically anything that is desiredpbut normally the amount Form shown in Figure 5 In the form shown :in this figure the wafer is member corresponding to' the arm 2I of Figure 2 and the lower member of the toggle is merely a short rigid arm-afiixed to-the blind slat. In this form a bracket 401s provided identical with the bracket I5 of the form in Figure 2. The blind slat 1, however, is directly pivoted by any suitable means to =-said bracket at the pivot point GI.

In the form shown anend plate 42 is provided having a substantial area and provided with openings 43 and 4 4 for-adjusting, as-by fastening screws, the blind slat at a selected one or" a plurality of possible angles with respect to the V The said operating arm is integral with the plate 42 and'pivots-in any conventional manner at the :point 46 to the upper arm of thetoggle The wafer, being here I 2 in the form shown in and the upper 50 of the said toggle member 47.

' points Its expansion or "contraction according to solar heat or ambient temperature, as determined by its surface finishing, causes said arm to lengthen or break up reflection of the sun's rays from the surface of the slat and thereby prevent objectionable reflection or glare.

Form shown in Figure 6 This form of blind is intended primarily for inside use and as shown in Figure 6 is mounted inside of the window by hanging from the top of the window casing immediately inside of the window sash.

A vertical support (id is aflxxed in a suitable manner to a base 6| which is in turn fastened to the undersurface'of the upper part 62 of the window casing. The blind slats 63 are pivoted in any conventional and convenient manner as 64 to said supporting rod 69 and are movable pivotally with respect thereto.

The operating rod 65 is similarly pivoted at 7 points 66 to the blind slats B3 and is aillxed at its upper end to a wafer 61 of the same general type as above illustrated and described in detail with respect to the form 7 This wafer is then fastened to a supporting element 68 which is in turn affixed to a base 89, which may or may not be integral with the base Bi, and said base is affixed to the window frame.

It will be evident upon inspection of the figure that as the wafer 61 expands or contracts in response either to the suns rays entering the window, or in response to the room temperature, the operating rod 65 will be caused to move downwardly or upwardly and the blind slats accordingly closed or opened.

Although this form has been shown for inside installation, it will be evident that this construction, hanging as it does from a single overhead support, will be applicable to either inside or outside installation.

It will be evident that many variations may be made upon the broad principles hereindisclosed to fit a wide variety of specific circumstances. For example, other temperature responsive elements, such as a bimetallic element, may be substituted for the expanding wafers shown, without altering the major principle of my invention. Accordingly, my development is believed to be of broad application, and such variations will all be included within the scope of my hereinafter appended claims excepting where said claims themselves expressly limit otherwise.

I claim:

1. In a heat responsive, automatically operating sun shading means, the combination: a substantially rectangular sun shading element; means for pivotally supporting said element on one of its ends; a bracket for pivotally mounting said element in fixed relation with an opening in the wall of a building; a heat responsive, expansible element aflixed on one of its sides to said shade element for pivoting therewith and extending in a direction away from said bracket; 9. link pivoted to the other of said sides of said exshown in Figure 2.

pansible means and extending therefrom substantially oppositely to the above mentioned bracket; a second bracket aiiixed rigidly with respect to the building wall and pivoted to the free end of said link.

2. In a heat responsive, automatically operating sun shading means, the combination comprising: a substantially rectangular sun shading element; a toggle unit including a pair of pivotally mounted links; means rigidly mounting said shading element to one link of said toggle unit; means providing a thermally responsive source of lineal mechanical motion integral with and constituting a portion of one of said links whereby variations in the length of said link in response to changes in temperature controls the pivotal position of said shading element.

3. In a temperature responsive automatically sun shading means, the combination comprising: a plurality of individual shading elements; a plurality of brackets each pivotally supporting one end of each of said shading elements; a plurality of pairs of pivotally attached toggle members each pair mounted to one of said brackets, one toggle member of each pair being rigidly attached to one of said shading elements; a thermal responsive lineally fluctuating element integral with and mounted intermediate the ends of and constituting a portion of one of said toggle elements whereby thermal changes are translated into fluctuations in length of said toggle element for changing the pivotal position of said shading element.

4. In a temperature responsive automatically operating sun shading means, the combination comprising: a plurality of individual shading elements; means pivotally supporting one end of each ofsaid shading elements; base means at the other of the ends of each of said shading elements; a plurality of pairs of pivotally jointed toggle members each pair pivotally mounted to said base means at the other of the ends of each of said shading elements, one toggle member of each pair being rigidly attached to one of said shading elements; a thermal responsive lineally fluctuating element mounted intermediate the ends of and constituting a portion of one of said toggle elements whereby thermal changes are translated into fluctuations in length of said one toggle member for changing the pivotal position of said shading element.

5. In a temperature responsive automatically operating sun shading means, the combination comprising: a plurality of individual shading elements; means pivotally supporting one end of each of said shading elements; base means at the other of the ends of each of said shading elements; a plurality of pairs of pivotally jointed toggle members each pair pivotally mounted to said base means at the other of the ends of each of said shading elements, one toggle member of each pair being rigidly attached to one of said shading elements; a thermal responsive lineally fluctuating element mounted intermediate the ends of and constituting a portion of the other member of each pair of said toggle elements whereby thermal changes are translated into fluctuations in length of said other toggle member for changing the pivotal position of said shading element.

6. In a temperature responsive automatically operating sun shading means as described in claim 5 wherein the central axis of said shading element is co-axial with the point of pivotal omounting of saidone toggle element to saidisul porting means.

'7. In a temperature responsive automatically operating sun shading means, the combination comprising: a plurality of individual shading elements; a bracket atone end of each of said shad- .0 ing elements; means at the other of the ends of each of said shading elements for pivotally supporting said shading element; a plurality of pairs of :piv-otally jointed toggle members, the free ends of each pair pivotally mounted to said bracket in fixed spaced relationship; one toggle member of each pair rigidly attached to one of said shading elements; a thermal responsive lineally fluctuating element mounted intermediate the ends of and constituting a portion of one of said toggle elements whereby thermal changes'are translated --int0 fluctuations in length of said one toggle member for changing the pivotal position of said shading element.

8. In a temperature responsive automatically operating sun shading means, the combination i comprising: a plurality ofindividual shading elements each constituting a thermal responsive 1 unit for fluctuations in thickness; a bracket at y "One end of each of said shading elements; means at the other of the ends of each of said shading elements for pivotally supporting said shading elements; a plurality of pairs of pivotally jointed toggle members, the free ends of each pair pivotally mounted to said bracket in fixed spaced relationship; o-ne'of said shading elements rigidly attached to one toggle member between the ends of said toggle member and in the direction of thickness fluctuation constituting a portion of said toggle member, whereby thermal changes l are translated into fluctuations in length of said -=one togglemember for changing the pivotal poone of said shading elements; a thermal responsive lineally fluctuating element mounted intermediate the ends of and constituting a portion of one of said toggle elements whereby thermal changes are translated into fluctuations in length of said one toggle member for changing .the pivotal position of said shading element.

JOHN J. GREBE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Taylor et al June 22, 1897 Brooinell Mar. 23, 1915 Fulton Nov. 9, 1920 Herrmann Dec. 25, 1923 LeGrand Oct. 13, 1931 Van Bosch et a1 Mar. 7, 1939 FOREIGN PATENTS Country Date Great Britain Nov. 2, 1933 Number Number 

